Magnetic and fluid regulation of electric current



June '3 1924. 1,496,136

c. H. SMOOT v MAGNETIC AND FLUID REGULATION OF ELECTRIC CURRENT Filed NOV. 19. 1920 IN VEN TOR.

Patented June 3, 1924.

I UNITED STATES'PATENT OFFICE.

cfia itns n. suoor, on NEW YORK, 11. Y.,

ASSIGNOR 'ro m'rmn BATTU snoo'r mi- GINEERING CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

MAGNETIC AIID FLUID REGULATION OF ELECTRIC CURRENT.

Application filed November 19, 1920. Serial No. 425,092.

To all whom it may concern:

Be it known that I, CHARLns H. SMoo'r, a citizen of the United States, residing at New York, 110 West 71st Street, have invented certain new and useful Improvement:

in Magnetic and Fluid Regulation of Electric Current, of which the following is a specification.

This invention relates to the regulation of electric current. I have devised means through which I correlate the pressures of a flow of fluid (gas or liquid) to the changes of electromagnetic forces derived from the electric current I wish to regulate. 16 The correlation between fluid pressures and electromagnetic forces is brought about by means of a variable size orifice interposed in the path of the fluid and controlled asto its size by the electromagnetic forces.

The means I employto carry out my invention are a lurality of solenoids, or the like, some moving, some stationary, in which electromagnetic force is generated n proportion to the current passing thro1.;gh the various windings. The current passing throu h the various windin s being the current wish to re late. T e relativeposition-of the solenoids varies the position of a valve which controls the size of the variable opening I interpo'se in the flow of fluid.

The contraction of'thc; orifice raises the fluid pressure and the enlargement of the orifice allows for a fall of fluid pressure.

The rise and fall of the fluid pressures LIB as the agencies through which I operate a rheostat, or the like, which in turn controls the 1 electric current I wish to regulate.

To those skilled in theart it will be plain that I have devised means whereby speeds of driving apparatus, strength of field coils,

etc., may be adjusted to maintain a given delivered result in power, current, voltage, etc., regulated in a predetermined manner. Referring to the drawing, the figure is a vertical, sectional view of an embodiment of my invention, in which Ihave used conventionalelectrical symbols.

As illustrated,the fi re shows the means I have-devised to maintain a constant po-'- m temtial between the leads of an' alternator.

Alternator A has. a direct current field B,

its leads being 0 and D. E is a direct ourront exciter, with shunt field coil F, driven by engine whereby a restricted amount of flui Solenoids 1 and 3 are stationary; 2 is a movable solenoid.

The connections between solenoids 1, 2 and 3 are such that a downward magnetic force is created, tending to pull the movable solenoid 2 downwards with a force increasing with an increasing potential between alternator leads C and D. This downward magnetic force, as well as the weight of solenoid 2 and connected parts, is counterpoised by the adjustable weight 6. Attached to the beam arm 4: is a stem 8. and the upper end of spring 7 the lower end of the spring being secured to the piston 9 of the dash pct 10. The rod 8 to which the spring 7 is secured passes freely through the piston of dash pct 10 which may be filled with oil. By-pass 32 is controlled by screw'31 in such a way that the resistance of oil passing from one side.

to the other of piston 9 is made adjustable. Dashpot 10 is afiixed to stem11, which in turn is affixed to the moving piston 12 operating in cylinder 14. 15 is a bent rod arm fulcrumed on lever 4 and terminating in a valve 16, riding under the orifice 17 18 is a pipe supplying fluid under pressure to operating cylinder 14.

Fluid enters the operating cylinder 14 through strainer 19 and exerts its pressure in the annular chamber 20, after passing through'p'ort 33. 21 is a needle type by-pass valve controllin the orifice area of ort 22, under pressure is admitted into the space 23 above piston 12. This operating fluid escapes from the cylinder through orifice 17, its quantity being controlled hv valve 16. 24 is a stufling box preventing the escape of fluid under pressure from annular chamber 20. 25 is a connectin rod, articulated to piston 12 and to lever 26 0% rheostat 27 The terminals of the rheostat 27 are connected b conductors 28 and 29 to the shunt field and exciter E. Solenoids 1 and 3 are stationary, while solenoid2 is aflixed to beam arm 4, which is fulcrumed by flexible member 30 to a -int of support 5.

he operation of the illustrated embodiment of my invention, described above, is as follows:

Adjustable weight 6 is made to counterpoise the magnetic force developed between solenoids 2 and 1, and 2 and 3, for the desired potentialbetween leads C and D of the downward effort exerted by solenoid 2 is reduced and the solenoid moves upward, carrying with it lever 4, arm andvvalve 16, which upward motion restricts the escape of fluid through orifice 17 resulting in an accumulation of fluid in chamber 23,,and

' downward motion is communicated to piston 12 b the increasing pressure in chamber 23. v T is downward motion of piston 12 opstates the rheostat 27, moving the lever 26 downward, and reduces the resistance in the field circuit of exciter E, whereby a greater potential is generated and the excitation of field B of alternator A is increased sufliciently to. restore the potential between alternator leads C and D to its original value.

. However, the potential at C, D does not immediately respond to the change in the rheostat and due to this lag there is liable to be set up beats, the lever 26 oscillating up and downin a periodic manner. To overcome this tendency to beats, I introduce the resilient member 7, between the lever 4 and the piston 12. The resilient member 7 allows a certain amount of overtravel of the rheostat are to temporarily compensate for the delay in the correction of the potential variation at C, D. For example, a rise in the potential at C, D will cause a downward movement of coil 2. This will compress the spring 7 and open the valve '16 quicker and to a greater extent than if there were no resilient member, whereupon the piston 12 will move upward, the resistance 27' will be increased and. excitation diminished would otherwise, which resu ts in a correction compensating for the lag and thus "doing away with objectionable oscillations or eats.

As the potential of the alternator is restored to its normal value, the departure from normal of magnetic force on solenoid 2 is reduced and the action of spring7 on lever 4, and thence on valve 16, causes piston 12 to return to normal position.

This action is complete for a very rapid change andrestoration of potential, but for a slow change of potential the flow of oil around piston 9 gradually releases the tension in spring 7, which producesa correspondingly reduced effort upon lever 4 and a reduced action in restoring piston 12 to its original position, so that the piston and its connected rheostat lever takes up a new position, although the coil 2 and its lever 4 will have returned to the middle or balanced position. v p a It will thus be apparent that thiscombinauicker than it tion of dashpot and spring compensates for the time delay between motion of control arm 26 in rheostat 27 and delay change in voltage between the leads C and D, due to the time necessary to increase the field current .in the field winding B and alternator A.

ratus shown is only an illustration andthat the invention can be carried out by other means. 7

'To those skilled in the art itwill be shown that I have devised means to correlate the magnetic forces of solenoids 1, 2 and 3, which are in proportion to electrical quantities developed with the pressure of a fluid flowing through and controlled by a variable orifice comprised by valve 16 and orifice 17, which orifice is under the dependence of the magnetic forces.

, On the one hand the magnetic forces are dependent on the electric current flowing from lead C and on the other hand rheostat 27 is operated by the pressure of thefluid in chamber 23.-

The correlationI have created between the magnetic forces and the fluid pressures causes the interaction of the electric current to pe regulated by the'rheostat for its contro The location of the rheostat in the electric system described is immaterial as regards the spirit of my invention and has been selected for an illustrative purpose only.

I claim: v v

1. Means .for regulating electric current which comprises in combination, electromagnetic devices responsive to changes in the current and correlating fluid "pressure devices controlling a flow of fluid, means responsive to said fluid pressure devices to vary the electric current to be controlled, and resilient means interposed between the electromagnetic devices and the fluid pressure responsive means, said resilient means being adapted to cause the fluid pressure responsive means to overtravel momentarily to correct tendency to beats.

2. Means for regul'atin electric current which comprises in com ination, electromagnetic devices responsive to changes in the current and correlating fluid pressure devices controlling-a flow of fluid, means responsive to said 'fluid pressure devices to vary the electriccurrent to be controlled, a responsive means to temporarily overtravel retarding device interposed between the to prevent the occurrence of beats when the electromagnetic devices and the fluid preschanges in current are temporary and the 10 sure responsive means, resilient means interretarding device allowing the fluid pressure posed between the electromagnetic devices responsive means to assume a new position and the fluid pressure responsive means, said when changes in current are Iprolon ed. resilient means allowing the fluid pressure v v C. SM OT. 

